Cell Definition and 956 Threads

The EMF of the cell is the potential of the cathode subtract that of the anode, consistent with ##\Delta G = -nF\varepsilon##. If the cell is running as a galvanic cell/discharging, the EMF should be positive. If it is charging, the cathode (the one gaining electrons) is now negative and at...

Suppose the emf of cell ##X## exceeds that of ##Y##, such that conventional current is driven in in an anti-clockwise direction. There is a little ambiguity in my mind about the circuit symbol for ##Y##. In the above setup, the larger bar of ##Y## is at higher potential and the smaller bar at...

1. Photons having enough energy to transmit an electron from the conduction band to the valence band must fall on the solar cell. 2. The cell is composed of a flat PN diode with the n-type layer on top. 3. As photons hit the n-layer, electrons and holes get formed. 4. Due to the voltage barrier...

Sorry if the answer is obvious, but I was wondering if positive and negative electrodes (cells in series) can share the same current collector as depicted below? I want to create a 12V battery with cells inline in series without creating cells with individual current collectors. Note that the...

The Inside-Out hypothesis, proposed in this paper (open access), explains the origin of several eukaryotic cellular structure based upon the cell geometry resulting from expansions cell protrusions becoming the cell's non-nuclear cytoplasm. Here is their summary diagram: and their caption...

This is a wonderful area of active research. Early in my EE career, I was interested in trying to use IC-scale nerve interfaces to bypass spinal cord injuries, but the science of interfacing electronics to nerve cells for long-term use was not developed enough. Even today, it is a problematic...

In regards to human vision and specifically the retina and ganglion cells. I find it hard to comprehend that somehow the light can only hit one part of the retinal ganglion cells (either the centre or the surround) and not the other? Doesn't light go everywhere? Is the lens focusing light so...

Encouraging news that the technology can potentially cure a number of genetic disorders https://www.npr.org/sections/health-shots/2019/11/19/780510277/gene-edited-supercells-make-progress-in-fight-against-sickle-cell-disease

what will be the joules per meter using thermal gain and wattage gain from a solar cell if the cell is in an insulative vacuum not counting the thermal degredation of 25% for wattage loss due to heat gain

Hi PF! I have a cell 1 X 5001. Each component within is a double matrix of different sizes, approximately 100 X 3. The entire cell is called a. Then when trying to extract component (1,2) from each of the 5001 matrices I type a{:}(1,2), but upon executing this MATLAB complains "Expected one...

Hi guys , I want to construct a primitive unit cell for diamond, which is made of a fcc lattice and a basis of 2 carbons atoms. I know that a primitive unit cell isn't unique but the two variants I get are drastically different . As far as I can see they both include 2 whole atoms/points in the...

Hello, I have a question in regards to electroplating. If i have a cell with let's say a zinc cathode and an inert anode in a solution of copper ions, and I turn on the current, what reaction will counter the reduction of copper ions to balance the electronegativity and what will be the...

Summary: How does a cell of SRAM work? I have computer science minor, and we have been given the task of finding out the differences between SRAM and DRAM. Simple enough? I thought so, until I got into the circuitry of a SRAM cell and got interested in finding how it works for storing, reading...

Hello, I am working through the MCNP manual and am experiencing the following error as well as warning when trying to run the sample problem from the manual. The fatal error I get is "fatal error. surface 0 not found for cell 1050." I have upload the output file with the errors in case I...

Hi. I am studying the effect of plasmonic nanoparticles on solar cells. Is there a way to calculate absorption efficiency in different layers of tandem solar cells in COMSOL Multiphysics.

Hi all, I am working on perovskite solar cell related studies. J-V curve (current density-voltage curve) is one of the important measurements to determine the performance of the device. In practice, we perform the reverse scan first then then followed by the forward scan. There is usually a...

Hi, googling for Voltaic cell I found this video about it. At minute 2:35 to 2:54 you can see that, without any electrical conductor connected between electrodes, in the Copper half-cell the metal electrode (Cathode) gets an amount of negative charges (electrons). Basically what described there...

My textbook states that all the 14 bravais lattices have one of the 7 types of parallelepiped (7 crystal systems) that can be used as an unit cell. However in case of 3D HCP textbooks don't talk about this parallelepiped, rather they consider a hexagonal prism as the unit cell. Why is it so...

A friend is writing a story in which somebody steals a frozen, non-fertilised ovum from an egg bank, meaning to do something with it (not sure what). The thief then forgets about it and finds the tube containing the ovum in her pocket a few days later. She looks at it under a microscope. The...

Can anyone explain why an artificial magnetic field may or may not promote an increase in cellular metabolism?

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Hello, consider again a simple Daniell cell with salt bridge in place but no external electric connection between electrodes. Reading from some source e.g. link1 it seems upon Zinc and Copper metal rods are dipped into their own ions solution, both will gain a negative charge (-) due to an...

Hello, I'm taking an energy class and I'll be giving a presentation on fuel cells. I was wondering if I could get some help understanding the whole process of the paper below. Unfortunately, I can't post the article because of copyrights. To summarize, it's a one compartment H2O2 fuel cell with...

Hi, having not a deep knowledge of electrochemistry I've some doubts about processes involved in a galvanic cell. Take for instance a Zn/Cu Daniell cell for which E0cell is 1,10V. That means emf for it is 1,10V. Starting to read from how battery works I had a first understanding of how...

Hi all - I have a question on the redox reactions in Li ion batteries. I'm not being able to figure out where the Li-> Li+ + e- half cell reaction is actualy happening. Take the standard LCO reaction: LiCoO2 + C6 -> LiC6 + CoO2 (in reality, only 50% of the Li reacts this way, but let's ignore...

A solar cell generates a potential difference of .1v when a 500ohm resistor is connected across it, and a potential difference of .15v when a 1000ohm resistor is substituted. What is A.) the internal resistance of the solar cell and B.) the emf of the solar cell I am a bit confused because...

Ok had to start this with a cell phone But need help even with first step Just focusing in on #3 #4 I think is related

Homework Statement A typical human cell is approximately 10 μm in diameter and enclosed by a membrane that is 4.2 nm thick. To simplify the calculations, model the cell as a sphere. 1) What is the volume of cell? (in μm^3) 2) What is the volume of cell membrane? (in μm^3) 3) Percent cell volume...

Used a P100 to pipette 93.6 micro-litres of fluid. There was an air gap in the pipette tip the first time I did it but no air gap the second time. I'm assuming there shouldn't be an air gap but can somebody tell me for sure?

For example, I don't understand slide 4, line 4 of the link below. I know that the first three numbers are the cell number, material number and density of water. But what do the next 6 numbers mean (2, -1, 4, -3, 5, -6)? Similarly on line 8, what do -0.001293 (101, -102, -100) mean? Thank you...

Fuel cells quickly provide electricity from H2 when switched on. But what exact steps get to Grid voltage? Are there many small inverters, and if so, how do they keep the output in step? What sort of efficiencies are there?

Is there such a thing of a protein (or some other biochemical) being coded to leave the cell, do something (or not) and then return for another function in the cell? Or in some way go "in and out" throughout its existence? Or at the least that would "take a leave of absence" and then become...

Hi, I am trying to determine the conventional cathode and anode designations for lead acid cells. From what I have researched: Anode is where current flows in the device, or where electrons flow out of. In a secondary cell the designations for anode and cathode are based on the discharge...

Biologically speaking, why I'm not a cell in my brain, or just heart, I'm me as a whole. How lucky was I to be myself as a whole, not just another cell inside my body?

Hi, I was playing this game in which you start from any cells of a 3x3 or 5x5 square and draw a line that loops through every cell in the box. The line can go only through a vertical or horizontal side (not diagonally). When you start from certain cells (problem cells), you can't reach at...

I have a device that is able to rotate on a shaft a weight of 40 pounds with less effort than it does to rotate a weight of 10 pounds on the same shaft. The rotation of the 40 pounds can be done simply by rotating the shaft by hand using only a slip motion. This design can rotate weights over...

I have read many sources on DNA and still have a few questions. Let me start with this one, and depending on the answers I will ask more. Question 1. f I were to look into a human cell how would I see the DNA? Is there a single very long copy of the DNA string or are there two copies. Question...

Hi All, (Just for information and understanding), If we have a concentration cell experiment like the image uploaded, in a concentration cell, the solutes are supposed to be of the same kind, iI.e. CuCl2 (?). I suppose it is possible to add to the left vat a m quantity or volume of CuSO4 to...

I was wondering what happens to all the "debris" that is absorbed by macrophages? Do they process them to the waste system or is it possible that they can feed them to the needs of neighboring cells? Or do these different chemical processes of eating nutrition vs getting rid of waste not mix...

I'm a high schooler involved in a research in which we aim to grow perovskite crystals in microgravity. I've recently come across this article (https://scitechdaily.com/researchers-develop-a-better-method-for-making-perovskite-solar-cells/) in which they explain how to grow better perovskite...

Hello, Can you tell me please the mass flow rate of hydrogen and oxygen per unit of area of electrodes in fuel cells? Or if you have information on the mass flow rate of hydrogen and air per volume of fuel cell stack? I understand this may vary, but I am looking for publications or other...

Homework Statement The EMF of the cell : Ni(s) | Ni2+ (0.1M) || Au 3+ (1.0M) | Au (s) is [ given E°(Ni2+/Ni)= -0.25V; E° (Au3+ / Au )= +1.50V ] Homework Equations E°cell=E°(cathode)-E°(anode) For SRP. Nernst equation The Attempt at a Solution SOP is given, therefore converting to SRP we...

https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(18)30117-4The authors do not seem to use the term bushy to describe the non-linear evolution of Homo sapiens, but other authors have used it. They use 'African multiregionalism' instead. And also they exclude panmyxia (free for...

Homework Statement Calculate E cell for the following reaction at 25deg celcius 3 CU(s) + 2 MnO4-(aq) + 8 H+(aq) →2 MnO2(s) + 3 CU^2+(aq) + 4 H2O(l) Given: [CU^2+] = 0.010M, [MnO4-] = 2.0M, [H+] = 1.0M I’ve posted a picture of my work, if someone could just let me know if I answered the...

Homework Statement 2 IO3−(aq) + 6 H+(aq) + 10 I−(aq) →6 I2(s) + 6 H2O(l) I didn’t want to re-type all of this up but I uploaded of picture of my work for this problem. I was just wondering if I completed it correctly and if not if someone could guide me in the right direction. Thank you!

Are there estimates of the number of different cell types in the human body?

LINE 1 transcripts have been shown to be necessary for mouse (and maybe all mammals?) embryos to go beyond their 2-cell stage in development. Science mag news article here. LINE (Long Interspersed Nuclear Elements) 1 are retrotransposons (mobile selfish DNA elements) that are found in...

Greetings, another question to the Pockels Effect, maybe someone can answer this. Pockels Cells are called "voltage controlled waveplates", since the voltage changes the birefringence of the material, leading to the same birefringence induced change of total polarisation plane than in wave...

Dear All, I've been recently reading the very clear text of Burns and Glazer entitled Space Groups for Solid State Scientists in the context of my thesis which requires understanding of symmetries of crystals, more specifically symmetries of (approximate triply periodic minimal surfaces)...

If Cellular network towers are supposedly divided in cells , like this image , then why do we loose connection even when outdoors and not inside or near any buildings/cars. Also why is it common to see more than 1 cell tower near each other?